To improve health patient oriented outcomes in Emergency Departments (ED) by deriving, validating, and comparing the Rasch Disability Diagnostic Tool (RDDT) to existing Measure of Disability (MOD) Research Design: This multi methodological study includes deriving a Rasch scale of disability: I) Using the RDDT to retrospectively score disability indicators, validating the RDDT, selecting a subset of the Rasch scale to be used as a brief measure for an ED randomized clinical trial;II) Prospectively, linking disability assessments to patient oriented outcomes (health care service utilization and mortality). This study would compare diagnoses to determine impact on patient outcomes and costs. Methodology: An expert panel would determine content for the disability diagnostic tool, Rasch scales would be created to score disability in existing hospital records in the retrospective phase. First, we would retrieve all disability assessments performed on ED patients (20-30 per day) since the inception of the electronic data collection system at Yale New Haven Hospital (April 2005). Second, we would score disability in ED records for patients >65 years and examine patient outcomes, treatments and referrals based on the assessment. Third, we would examine how the assessment impacted ED patient oriented outcomes. The retrospective phase of this study would allow us to track subsequent Yale hospital and ED visits, treatments, and health outcomes. A brief accurate and precise RDDT, developed in the retrospective analysis would be used for the prospective phase to compare with the existing MOD in a randomized clinical trial. 600 patients would be recruited over the course of the study and randomly allocated into the MOD (control) or RDDT (test) arm. Consented study subjects, including ED patients, families, and patient health care providers would be followed for two months. The primary patient outcomes, ED visits, hospital admits, and mortality would be quantified for comparative purposes. We would estimate the number of preventable ED visits and hospitalizations and provide a cost benefit for adopting the RDDT in EDs. Finally, the RDDT would rely on health information technology. The exploratory aim of the study would assess work flow, time and cost savings, efficiency and usability for use in the ED. Potential Impact on Health Outcomes: We expect that a better disability diagnostic tool would lead to lower mortality, a reduction in unnecessary costs, preventable ED visits and hospitalizations, and a better quality of life for patients presenting to Emergency Departments. PUBLIC HEALTH RELEVANCE: Increasing numbers of elderly and/or disabled persons are presenting to Emergency Departments (ED) that require an assessment of their disabilities for treatment and proper referral. ED physicians are often at a loss because these patients do not require acute care or hospitalization yet their failure to thrive in the community brings them repeatedly to the ED where their needs are not being met. This study aims to improve the health outcomes of persons presenting to EDs by developing and validating a disability diagnostic tool that would allow ED physicians to connect these patients to better health care referrals, proper long term care services, and other non-ED health care providers.